Not passive annual tax but gantry based instant electronic road pricing. Charge for using arterial or corridor roads.

Example: Bellary road from Hebbal flyover thru CBD all the way to Silkboard flyover and continuing on to BETL. This will become feasible once the corridor becomes signal free, so those going across the road wont be charged. Rs 50 every time your vehicle enters the road or leaves it (Rs. 100 min). Public transport should be exempt (bus, surface rail etc). 

Sample reading on congestion pricing courtesy wiki http://en.wikipedia.org/wiki/Congestion_pricing

Continue to vote your option. Public Transport needs incentives. Shouldnt this be one of them?

It would be interesting to hear some comments from the people who say 'NO' to the poll on the rationale behind the 'NO'

 Well, most of the companies provide pickups and drops. This can also be considered as Public Transport since it is pooled one. We know many complaints about BMTC as an excuse to get away from this, atleast office transport should be used for office commute.

People would always complain that  Public Transport is not good to get away from this. But, many are already using them. 

Dedicated lanes, or magic boxes just for buses. That would be a more effective though indirect tax on private vehicles.

By tax, I assume you mean toll for using the arterial (radial) roads.